The present invention relates to a cord locking assembly for use with a Venetian blind. When the blind lift cords are released from the cord locking assembly, the blind falls under its own weight. The invention relates more particularly to improvements in a locking mechanism by which the blind is prevented from suddenly falling when the lift cords are released from the cord locking assembly.
The known cord locking assembly has a fixed member, a movable member resiliently biassed to the fixed member, and a releasing member to move the movable member away from the fixed member. The lift cords are locked between the both members when the releasing member is free, and released from the locking between the both members when the releasing member is operated to move the movable member away from the fixed member.
The cord locking assembly as disclosed in JP B 57-55863 has a hollow pole suspended from the head box, a hand grip axially movably fitted on the lower end portion of the pole, lift cord ends extended outwardly from the bottom of the grip, and a cord locking assembly mounted within the hand grip. The assembly has a plug hole formed in the bottom off the pole and a plug fixedly mounted within the grip for fitting engagement with the plug hole. The lift cords pass through between the plug and the plug hole. The plug is biassed upwardly to the plug hole under the action of a compression spring interposed between the pole and the grip.
When the grip is released, the compression spring raises the grip and inserts the plug into the plug hole so that the lift cords are locked between the plug and the plug hole. Then, the lift cords are locked to rest the blind at that position.
When the cord ends are pulled down by hand against the friction between the plug and the plug hole under the action of the compression spring, the blind is lifted.
When the grip is drawn down by hand against the compression spring, the plug is caused to slip out of the plug hole so that the lift cords are unlocked. Once the lift cords are unlocked, the blind falls suddenly under its own weight. When the blind is at a high position, it will fall at dangerous speeds, unless a person pulls down the grip by one hand to unlock the lift cords while he holds the lift cord ends by the other hand to prevent the rapid fall of the blind. But, it is not easy to operate the grip by one hand and the cord ends by the other hand.